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We present here a first principle method for the calculation of effective cluster interactions for semi-infinite solid alloys required for the study of surface segregation and surface ordering on disordered surfaces. Our method is...
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We present here a first principle method for the calculation of effective cluster interactions for semi-infinite solid alloys required for the study of surface segregation and surface ordering on disordered surfaces. Our method is based on the augmented space recursion coupled with the orbital peeling method of Burke in the framework of the TB-LMTO. Our study of surface segregation in CuNi alloys demonstrates strong copper segregation and a monotonic concentration profile throughout the concentration range. (author). 35 refs, 4 figs, 2 tabs. (Atomindex citation 26:078866)
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We present here a technique for the calculation of configurationally averaged quantities in reciprocal k- space representation, like the spectral function and complex band structures. We apply the technique to AgPd alloys in conju...
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We present here a technique for the calculation of configurationally averaged quantities in reciprocal k- space representation, like the spectral function and complex band structures. We apply the technique to AgPd alloys in conjunction with the tight-binding linearized muffin tin orbitals basis. We also indicate why the same technique is ideal for application to the more accurate screened-KKR and allows us to go beyond the single site coherent potential approximation and include multi site effects like short-ranged ordering and local lattice distortions due to size mismatch of the constituent atoms. (author). 10 refs, 2 figs. (Atomindex citation 26:069040)
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The problem of quantum transport through waveguides of different shapes and disorder has been of considerable interest recently, particularly in the study of mesoscopic systems and nanostructures, where quantum coherence is basic ...
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The problem of quantum transport through waveguides of different shapes and disorder has been of considerable interest recently, particularly in the study of mesoscopic systems and nanostructures, where quantum coherence is basic to the study of motion of electrons. We present here a generalization of the vector recursion technique of Haydock and Godin and Haydock for the calculation of the scattering S-matrix for a three dimensional slab attached on two ends by perfectly conducting three dimensional leads. (author). 11 refs. (Atomindex citation 26:039737)
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Following a two-potential embedding approach, we study the electronic structure of disordered binary alloys taking short-range order effects into consideration. (author). 4 refs, 3 figs. (Atomindex citation 19:090295)
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A generalization of the single site KKR-CPA to include effects of clustering is presented here. The formalism combines the usual KKR ideas with the augmented space formalism introduced by the author. 15 references, 2 figures. (ERA...
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A generalization of the single site KKR-CPA to include effects of clustering is presented here. The formalism combines the usual KKR ideas with the augmented space formalism introduced by the author. 15 references, 2 figures. (ERA citation 12:029732)
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A priori, it is not clear how to split the total intensity of thermal neutron scattering from disordered alloys into a coherent and an incoherent part. We present here a formalism to do this. The formalism is based on the augmente...
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A priori, it is not clear how to split the total intensity of thermal neutron scattering from disordered alloys into a coherent and an incoherent part. We present here a formalism to do this. The formalism is based on the augmented space technique introduced earlier by one of the authors. It includes disorder in mass, force constants and scattering lengths. A self-consistent CCPA which is tractable for realistic calculations is presented for the coherent and incoherent intensities. This is expected to prove useful in theoretically analysis data for alloys (e.g. Nisub(x)Ptsub(1 - x), Nisub(x)Pdsub(1 - x), Nisub(x)Crsub(1 - x)) for which it is necessary to go beyond the usual single site CPAs for reliable accuracy. (Atomindex citation 16:066465)
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The augmented space scattering diagrams for the conductivity for random binary alloys have been examined in detail. Within a CCPA it is seen that in addition to the 'uncorrected' conductivity calculated from averaged currents ther...
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The augmented space scattering diagrams for the conductivity for random binary alloys have been examined in detail. Within a CCPA it is seen that in addition to the 'uncorrected' conductivity calculated from averaged currents there are three types of corrections: the vertex correction (non-vanishing except in the 1CPA with diagonal disorder), the corrections to the averaged current and a non-separable correction term. A tractable graphical method for obtaining these corrections is described and an application is made to a simple, three-dimensional alloy model. (Atomindex citation 16:075979)
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A formalism has been developed for the study of optical conductivity of disordered semiconducting alloys effect of off-diagonal disorder, clustering and randomness in the electron-photon interaction matrix may be incorporated with...
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A formalism has been developed for the study of optical conductivity of disordered semiconducting alloys effect of off-diagonal disorder, clustering and randomness in the electron-photon interaction matrix may be incorporated within this. The aim is to finally study GaAssub(x)Sbsub(1-x) as well as deep levels in this alloy. (Atomindex citation 16:030141)
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Based on the augmented space formalism introduced by one of us and the use of the Ward identity and the Bethe-Salpeter equation, a formalism has been developed for the calculation of electrical conductivity for random alloys. A si...
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Based on the augmented space formalism introduced by one of us and the use of the Ward identity and the Bethe-Salpeter equation, a formalism has been developed for the calculation of electrical conductivity for random alloys. A simple application is made
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The magnetoresistance of spin glass alloys is examined within the percolation model of Mookerjee and Chowdhury (1983), the mode freezing model of Hertz (1983) and the constrained relaxation model of Palmer et al. (1984). All three...
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The magnetoresistance of spin glass alloys is examined within the percolation model of Mookerjee and Chowdhury (1983), the mode freezing model of Hertz (1983) and the constrained relaxation model of Palmer et al. (1984). All three models yield qualitatively similar results in excellent agreement with the experiments of Majumdar (1983, 1984) on AgMn. (Atomindex citation 16:060181)
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